1. Field of the Invention
The present invention relates to a portable image pickup device which is capable of capturing a still image and a moving image, and more particularly to a portable image pickup device which is capable of previously preventing a recording operation from being interrupted due to a restriction in a storage capacity depending on a file system.
2. Description of Related Art
A compact portable image pickup device which has a storage portion such as a large-capacity hard disc drive or a memory, and which can photograph a moving image in addition to a still image in a state of being held by one hand of a user has been proposed as a conventional portable image pickup device.
In such a portable image pickup device, while depending on a capacity of a storage portion, a lot of data on captured images can be stored in the storage portion without requiring a work such as a film exchange as in a conventional film camera. Thus, a user often only notices that the photographing is impossible when the storage capacity of the storage portion has been filled up. The portable image pickup device has a function of displaying data on a remaining capacity of the storage portion as means for previously preventing such a situation from being caused.
With regard to a file system for managing how a file is recorded in a storage portion for storing therein data on an image, a moving image and the like, a file allocation table (FAT) or a file allocation table 32 bit (FAT32) has been widely used as a file system which is high in general applications. However, there is a restriction in an amount of data per one file which can be created in such a file system. For example, an upper limit of an amount of data per one file in the FAT32 is decided as 4 GB in terms of the file storage standards. Thus, even when there is still a remaining capacity in the storage portion, an amount of data per one file does not exceed 4 GB at all. As a result, if data having a capacity exceeding 4 GB is recorded, it will be recorded straddling over a plurality of files.
As for an image pickup device in which a problem is dissolved that no data can be recorded any more in spite of existence of the remaining capacity in the storage medium, an image pickup device has been known in which the number of creatable files in a storage medium is calculated in accordance with the file storage standards, and the number of sheets of files for data recordable in the storage medium is calculated, and a value of the number of files which is smaller one between them is displayed as the number of sheets of the files for photographable images on a displaying portion in accordance with the comparison between them, and also this effect is alerted. This image pickup device, for example, is disclosed in the Japanese Patent Kokai No. 2003-158645.
However, according to the image pickup device disclosed in the Japanese Patent Kokai No. 2003-158645, the display cannot be previously made when an amount of data outputted from the image pickup element changes momentarily as in the case of the moving image. For example, during the photographing of the moving image for which a variable bit rate is selected in which an amount of data processed per unit time changes, an amount of data changes while the data is recorded. As a result, there is encountered such a problem that since an amount of data changes during the recording operation, it is difficult to precisely display information on recordable data, and when an amount of data used reaches 4 GB, a file in which the data is being recorded is closed due to the restriction in the FAT32 described above, and the recording operation is temporarily interrupted because the data must be continuously recorded in a new file.